Straightening machine



May 24, 1932. Q sTlEFEL 1,859,851

STRAIGHTENING MACHINE Filed Aug. :5, 1951 WITNESS Patented May 24, 1932RALPH C. STIEFEL, 0F ELLWOOD CITY, PENNSYLVANIA STRAIGHTENIN G MACHINEApplication filed August 3, 1931.

The invention relates to machines, for

straightening round metal stock, such as tubes, rods, shafts, and thelike, the object being to provide a machine for this purpose which issimple in construction, and hence economical to manufacture and operate,and

I which effectively removes short kinks as well as large bends fromround stock.

The invention is illustrated in the accompanying drawings of which Fig.1 is a somewhat diagrammatic plan view of a set of rolls forming theessential parts of the machine,with a tube in the line of pass throughthe rolls; Fig. 2 a side view of the machine 7 with the near rollremoved to show the straightening action of the machine; and Fig. 3 anend view of the machine.

The straightening machine provided according to this invention comprisesa set of three rotatable cross-rolls mounted in a suitable frame orhousing, each of the rolls being adapted to be driven. The rolls are somounted that their axes are inclined to each other and to a pass linelying cent-rally of the rolls, which are adjustable radially of the passline for straightening round stock of different diameters, and which mayalso have the inclination of their axes adjusted for the same purpose.The faces of two of the rolls are concave between their ends to form apocket for receiving stock which is deflected progressively by anannular projection formed on the central portion of the third roll. Bothends of all three rolls are provided with annular projections whichcollectively form at each end of the rolls threepoint stock-engagingfaces spaced equidistant from the central pass line for holding thestock firmly in the pass line at each end of the pocket formed by theconcavities in the faces of the two first-mentioned rolls.

Having reference to the illustrative embodiment of the invention, a setof three rolls 1, 2 and 3 is shown grouped around a central pass line 4,which is the axis of a tube 5 illustrated as being subjected to thestraightening action of the rolls. As illustrated, the rolls areprovided with'suitable journals 6, 7 and 8 adapted to be mounted insuitable adjustable bearings, and by which each of Serial No. 554,841.

the rolls may be driven on their respective axes which-are inclined toeach other and to pass line 4. The faces of rolls 1 and 2 are providedwith curved concavities 9 and 10, respectively, and the mid-portion ofthe face of roll 3 is provided wit-h a curved annular projection 11,which, in the throat or center 12 of the pass, is opposite to thedeepest portions of concavities 9 and 10.

Adjacent to their ends, concave rolls 1 and 2 are provided withlongitudinally-curved stock-engaging annular faces 15 and '16, re-

spectively, the preferred extent of which, as measured along pass line4, is indicated by the dimension lines A in Fig. 2. In a similar manner,roll 3 has its end portions provided with curved stock-engagingprojections 17 indicated in Fig. 2 as being of the same extent as thecorresponding projections 15 and 16 of the concave rolls. By suitablyadjustin the axes of the several rolls, these extende end projectionsafford substantial line engagements of round stock on each side of thepocket formed by the concave rolls, and at each end of the pass. Thus,as shown in Fig. 3, there are extended three-point supports for a tube5, each point of support being equidistant from the axis of the tube,yvhioh, as stated, normally lies in the pass In the operation of themachine, the rolls are driven to feed round stock spirally onits axisand along the pass line of the ma chine. The medial annular projection11 of roll 3 is of such height with relation to the stock-engaging endportions 15, 16 and 17 of the rolls that projection 11 progressivelydeflects a straight tube up to, or substantially to, its elastic limit,the pocket formed by the concavities 9 and 10 of rolls 1 and 2 being ofsuch depth as to receive this amount of deflection of the stock. As tosuch portions of round stock as have no kinks or bends, the stock ismerely progressively deflected and comes out of the machine in itsoriginal straight form. Where kinks or bends occur the deflection of thestock is be 0nd its elastic limit, so that the kinked or ent portionsemerge straight. I y

In; the operation of this straightening machine, I have found that byfirmly engaging stock at relatively close intervals by the end portionsof three cross-rolls, and by progressively deflecting the stock by aprojection formed on one of the rolls into a relatively short pocketformed by concavities on the other rolls, short kinks and large bendsmay be effectively and quickly removed from round stock. The machinebeing simple in construction, it is economical to manufacture andoperate.

According to the provisions of the patent statutes I have explained theprinciple and operation of my invention, and have illustrated anddescribed what I now consider to represent its best embodiment. However,I desire to have it understood, within the scope of the appended claims,the invention may be practiced otherwise than as illustrated anddescribed.

I claim:

1. A machine for straightening round stock, comprising a set of threerotatable cross-rolls having their axes inclined to each other and to acentral pass line, the faces of two of the rolls being concave betweentheir ends to form a pocket for receiving progressively deflected stock,the mid-portion of the third roll having its face provided with anannular projection for progressively deflecting stockinto said pocket,and the ends of the three rolls being provided with annular projectionscollectively forming at both ends of the rolls three-pointstock-engaging faces spaced equidistant from said central pass line tohold the stock firmly in said pass line at each end of said pocket.

2. A machine for straightening round stock, comprising a set of threerotatable cross-rolls having their axes inclined to each other and to acentral pass line, the faces of two of the rolls being concave betweentheir ends to form a pocket for receiving progressively deflected stock,the mid-portion of the third roll having its face provided with anannular projection for progressively deflecting stock into said pocket,and the ends of the three rolls being provided with extended annular andlongitudinally curved projections collectively forming at both ends ofthe rolls three-point stock-engaging faces spaced equidistant from saidcentral ass line to hold the stock firmly in said pass ine at each endof said pocket.

In testimony whereof, I sign my name.

RALPH C. STIEFEL.

